The phrase "fatuous smile" refers to a smile that is foolish, silly, or lacking in intelligence. It suggests that the person wearing the smile is unaware of their surroundings or the seriousness of the situation. In colloquial use, “fatuous” describes something as lacking in sense or intelligence. The phrase tends to be used more in written contexts, often in literature or critiques, than in everyday oral speech.
Frequency of Use This phrase is relatively uncommon in everyday conversation but is found more frequently in literary, formal, or critical writing.
His fatuous smile belied the seriousness of the meeting ahead.
His silly smile concealed the gravity of the meeting that was to come.
She wore a fatuous smile throughout the presentation, oblivious to the tense atmosphere.
She maintained a foolish smile during the presentation, unaware of the tense mood around her.
The fatuous smile on his face only irritated his colleagues further.
The silly grin he had on his face only frustrated his coworkers even more.
The term "fatuous" may not appear frequently in common idioms but can be contextually related in phrases that convey a similar sentiment. Here are a few examples using the concept of foolishness or lack of awareness:
He was just playing the fool with his fatuous smile during the important meeting.
He was only acting foolishly with his silly grin during the crucial meeting.
In a world of one's own
With that fatuous smile, it seemed she was in a world of her own.
With her foolish grin, it looked as though she was completely detached from reality.
Grinning like a Cheshire cat
After receiving the news, he couldn't stop grinning like a Cheshire cat with his fatuous smile.
After hearing the news, he continued to smirk happily with his silly grin.
All smiles
The word "fatuous" comes from the Latin "fatuus," meaning "foolish" or "silly." It was borrowed into English in the early 17th century. The word "smile" originates from the Old English "smīel," which is related to the Proto-Germanic "*smīlaz" meaning to smile or laugh.